Vanderbilt Summer Science Academy

Investigation into PPP1ca and Hdac2 activities in immediate early gene transcription

The molecular control of gene expression is important during cellular decision-making of cell types during tissue growth and development, as well as neurodegenerative diseases such as Alzheimer’s. Immediate early gene (IEG) expression turns on when a memory is formed. We investigated the role of the enzymes Ppp1ca and Hdac2 in IEG expression. Ppp1ca is a phosphatase and Hdac2 is a histone deacetylase that remove phosphorylation and acetylation marks, respectively, on histones. We used qPCR (quantitative polymerase chain reaction) to monitor the amplification of the immediate early genes in each specific treatment. To test whether Ppp1ca and Hdac2 enzymatic activities were required for activating early gene expression, we used specific chemical inhibitors to block enzymatic function with/without KCl stimulation, which depolarizes cells. Our preliminary data suggests the inhibitor for PPP1ca with KCL stimulation further activated two different immediate early genes Fos and Erg1. Experiment replications are required to confirm these results. Since both enzymes are linked to similar function in the mammalian brain, we can test whether Ppp1ca and Hdac2 act synergistically in the same molecular pathway, leading to gene expression in Fos and Erg1. Preliminary data suggests there is little to no change. Finally, we have cloned the cDNA of both enzymes and will apply the novel CRISPR/Cas9 genome-editing approach to address whether overexpression of either Ppp1ca or Hdac2 affects immediate early gene expression of Fos and Erg1. Elucidating the effect of Ppp1ca and Hdac2 will be informative when creating treatments for learning disabilities and/or degenerative brain diseases.